Numerosity estimation as a function of stimulus organization.

It was proposed that stimulus organization of a set of homogeneous items can best be measured by using the mean distance to nearest neighbours. Patterns of dots were generated that fell on four different positions along the cluster continuum, from highly regular, through random, to clustered. When thirty subjects were asked to judge numerosity, their estimates decreased significantly as cluster measures increased. Four possible interpretations of the effect of organization on numerosity perception are discussed.     

Associative response heterogeneity: an indicator of stimulus word semantic autonomy

The total number of different responses, given by a group of subjects to a stimulus word in a single-word, free-association situation ( D ), is a primary determinant of associative response latency (Tecce & Glassco, 1965; Flekkøy, 1981). D has traditionally been assumed to reflect a word's associative potential, and the increased latency to high D words has been explained by response competition. The results of the present experiments indicate, however, that D reflects in an inverse manner semantic autonomy , high D words requiring more contextual information for their semantic specification than low D words. The process of semantic specification requires time, creating the positive D -response latency relationship. Based on a semantic interpretation of D , associative response heterogeneity may be used as an index of a word's semantic autonomy.     

Visual search with meaningful and non-meaningful material

Two experiments are reported which attempt to assess the effects of variations in target word, context items and instructions on performance in a visual search task. In Experiment 1, subjects were required to search through context lists of three-letter nonsense syllables (of either high or low association value) for three-letter meaningful target words (of either high or low frequency). They were given either “positive” or “negative” instructions, i.e. were told either to pick out the meaningful word or to pick out the word which was not a nonsense syllable. The results showed that visual search times were significantly influenced by both frequency of target word and association value of context items. A significant interaction was observed between type of instructions and target word frequency. The design of Experiment 2 followed that of Experiment 1, with the exceptions that nonsense syllables now became target items, and meaningful words formed the contexts. Again, nonsense syllable association value and word frequency were found to be critical in determining visual search times.     

Wind as an aversive stimulus

Two monkeys were trained on an escape-avoidance procedure in which a lever press delayed exposure to wind by 20 sec. For 5 hr, subjects alternately worked 15 min and rested 15 min, and performed this schedule when the wind was 5, 10, and 20 mph and the temperatures were 50, 60, and 70° F. Analysis of variance showed that the percent of wind avoided was related to both the velocity of the wind and the temperature during the exposure. When the wind was 10 and 20 mph it was avoided almost continuously regardless of the temperature.     

Levels of perceptual processing as a function of stimulus material and spatial location

Craik and Lockhart (1972) have proposed a framework for human memory research which is based on levels of processing. Most of the studies which support this approach have been concerned with comparing structural vs. semantic tasks. The present paper extends the levels of processing approach to earlier stages of processing and emphasizes levels ofperceptual processing. It is suggested that depth of perceptual processing depends on the nature of the stimulus material. Neisser’s (1967) theory of preattentive mechanisms and focal attention is shown to be a theory of levels of perceptual processing. Differences in the nature in which these two processes operates are discussed.     

Time flies when you're having fun: temporal estimation and the experience of boredom

Boredom is a common experience in healthy individuals and may be elevated in various neurological or psychiatric conditions. As yet, very little is known about the cognitive or neural bases of the subjective experience of boredom. We examined temporal perception and the temporal allocation of attention in healthy individuals reporting high- or low-levels of boredom. We found no difference in high- or low-boredom-prone individuals in the temporal allocation of attention, while individuals who experienced low-levels of boredom tended to underestimate time more so than high-boredom-prone individuals. Furthermore, high-boredom-prone individuals demonstrated higher error values when estimating time indicating that the subjective perception of the passage of time may be a critical component to the experience of boredom.     

Pigeons learn stimulus identity and stimulus relations when both serve as redundant,relevant cues during same-different discrimination training

The authors taught pigeons to discriminate displays of 16 identical items from displays of 16 nonidentical items. Unlike most same-different discrimination studies--where only stimulus relations could serve a discriminative function--both the identity of the items and the relations among the items were discriminative features of the displays. The pigeons learned about both stimulus identity and stimulus relations when these 2 sources of information served as redundant, relevant cues. In tests of associative competition, identity cues exerted greater stimulus control than relational cues. These results suggest that the pigeon can respond to both specific stimuli and general relations in the environment.     

Unconscious phantasy as an obstacle and as a stimulus to knowledge

This paper underlines and explores the connections between emotional and cognitive development at a very early stage, starting from the psychoanalytic psychotherapy of a 4-year-old boy with autistic features. Development of the personality and development of the mind are shown to proceed together and to be interwoven when the therapist starts to help the child to modulate the terror and the rage related to separation. The development of the idea of a good nipple and the Introjection of it as a mental structure is considered an important step on the way towards separation between mother and baby and towards the formation within the baby self of a space where symbols of the external world can be placed. Autistic features are considered as an extreme form of denial of both internal and external reality.